The present invention relates to internal combustion engines and more particularly to the problem frequently encountered of restarting an automobile engine while it is still hot.
It has been found that despite complete and careful engine tune-ups, as well as major overhaul of the carburetor including particular attention to the fuel level and antipercolator valve, many engines will not start immediately while they are still hot. Depending primarily on how hot the engine is when it is turned off and on weather conditions, the car may be hard to restart for fifteen minutes or more, and in some cases for as long as four or five hours, after it has been shut off. In such situations the engine may have to be cranked over continuously by the starting motor for a full minute before it will fire. This of course places a severe drain on the battery, and contributes to pollution of the atmosphere when the engine finally starts and discharges quantities of partially burned exhaust gases.
It is common knowledge among automobile mechanics that simply by removing the air filter, the engine will usually start right away. The generally accepted explanation of the cause of "hot" starting problems is that gasoline fumes seep into the housing of the air filter and produce a flooding effect. However, contrary to this reasoning, I believe that non-combustible gases accumulate in the housing of the air filter, so that when the engine is turned over to start it, the air fed to the cylinders is so contaminated with unburnable fumes that it is incapable of supporting combustion of the fuel. Consequently, it is necessary to turn the engine over for a relatively long time before the incombustibles in the air filter can be drawn through the engine and clean air mixed with the fuel to produce the required mixture for combustion. Although the problem may be overcome by removing the air filter in which the non-combustible fumes accumulate, most people who drive an automobile do not want, or are not equipped, to do this, especially with the multitude of connections now being made to the air filter for emission control purposes.
On the other hand, by following the usually recommended procedure of holding the gas pedal down on the floor in order to open the throttle valve completely and at the same time turning over the engine, the non-combustible fumes may eventually be cleared out and the engine started without removing the air filter. Unfortunately, this practice frequently leads to further complications, such as flooding by pumping the gas pedal, which aggravates the problem instead of solving it. Furthermore, even if the engine starts by holding the gas pedal down in this manner, the non-combustible fumes pick up fuel and produce smoke which adds to pollution of the atmosphere.
I am not aware of any attempts to overcome hot-starting problems, other than those referred to hereinbefore. In addition, I believe I am the first to discover the real cause of the problem and to provide a simple and inexpensive way of overcoming it.